JERUSALEM, Israel -- Many in the West have been anticipating an Israeli military strike against Iran's nuclear programs. However, a different kind of attack could already be underway. A mysterious cyber worm may be eating away at Iran's nuclear ambitions.

It's known as Stuxnet -- a computer worm or malicious software that Iran says has infected some 30,000 PCs -- some of them even belonging to workers at the Bushehr nuclear power plant.

"Apparently it's not industrial espionage, which is something we've come to expect," said Yael Shahar, who heads the database program at the International Policy Institute for Counter-Terrorism (ICT), Herzliya, Israel. "Most of these things are industrial espionage worms."

While Iran has accused the West of targeting its nuclear program, it denies that the worm has infiltrated any control systems.

Shahar said no one knows exactly the extent of the damage.

"However, there have been bits and pieces of information trickling out of Iran for two years about accidents and setbacks and delays and in the summer of 2009 in fact there was a serious accident at least according to Wikileaks," she said.

Some suspect the worm is a government sanctioned project, costing as much as $3 million and taking up to a year of work.

"This is a form of cyber warfare essentially," Shahar added.

One theory about the origin comes from the word "myrtus," appearing in the worm. That's a myrtle plant, known in Hebrew as Hadassah. Hadassah is also the name of biblical Queen Esther, who saved the Jewish people from destruction at the hands of a Persian king.

"Israel definitely could have done something like that," Shahar said. "So could the U.S. My guess - and this is just a completely uneducated guess, sort of a hunch - is that this would be more likely to be the work of the U.S., Israel and/or NATO or some of the European countries."

According to media sources, both the U.S. and Israel have been involved in previous attempts to sabotage the Iranian nuclear program.

The worm wouldn't likely scuttle Iran's entire nuclear program but Shahar said it could create delays and erode Iranian confidence in it.